Some recreational vehicles, such as all-terrain vehicles (ATV's), utility vehicles, motorcycles, etc., include a power steering system. Electronic power steering systems often use a detected ground speed to determine the level of steering torque assist to provide to the steering assembly. In these systems, the power steering will not function properly when ground speed data is faulty or unavailable. In addition, the calibration of a power steering unit may drift over time, resulting in a steering offset bias.
The stability of recreational vehicles may be assessed by stability tests, such as a static (KST) stability test, a rollover resistance rating (RRR) test, and a J-Turn test. Many recreational vehicles lack an active stability control system.
In an exemplary embodiment of the present disclosure, a vehicle is provided including an electronic power steering system, an electronic throttle control system, and a stability control system.
More particularly in a first embodiment, a power steering method for a vehicle is disclosed, where the method includes detecting, by a controller of a power steering system, a speed of an engine of the vehicle; determining, by the controller, a power steering assist level based on the engine speed; and outputting, by the power steering system, steering torque assistance to a steering assembly of the vehicle based on the power steering assist level.
In another embodiment, a power steering method for a vehicle includes detecting, by a controller of a power steering system, an error with a ground speed feedback signal; changing, by the controller, a power steering assist control mode from a first control mode to a second control mode in response to detecting the error with the ground speed feedback signal, wherein in the first control mode the controller determines a power steering assist level based on the ground speed feedback signal and in the second control mode the controller determines the power steering assist level based on at least one of a throttle valve opening, a detected engine speed, and a predetermined fixed ground speed; and outputting, by the power steering system, steering torque assistance to a steering assembly of the vehicle based on the power steering assist level.
In another embodiment, a power steering method for a vehicle includes detecting, by a controller of a power steering system, a selected gear of a transmission of the vehicle; determining, by the controller, a power steering assist level based on the selected gear of the transmission and a user torque input to a steering assembly of the vehicle; and outputting, by the power steering system, steering torque assistance to the steering assembly of the vehicle based on the power steering assist level.
In another embodiment, a power steering system for a vehicle, includes a steering assembly including a steering shaft; a sensor operative to detect a speed of an engine of the vehicle; and a power steering unit including a controller in communication with a motor, the motor being operably coupled to the steering shaft, the controller including control logic operative to determine a power steering assist level based on the engine speed, the controller controlling the motor to output steering torque assistance to the steering shaft based on the power steering assist level.
In another embodiment, a method for controlling a power steering system of a vehicle including: detecting, by a controller of the power steering system, a trigger event; in response to detecting the trigger event, determining, by the controller, a torque offset of the power steering system; and in response to the torque offset exceeding a threshold for each of a plurality of occurrences of the trigger event, determining, by the controller, a torque offset correction value; and controlling, by the controller, a steering torque assistance applied by the power steering system to a steering assembly of the vehicle based on the torque offset correction value.
In yet another embodiment, a recreational vehicle includes a chassis; an engine supported by the chassis; a ground engaging member; a steering assembly operably coupled to the ground engaging member; a power steering system including a steering shaft, a power steering unit, and a controller in communication with the power steering unit; and a torque sensor in communication with the controller, the controller being operative to detect a trigger event, in response to the detection of the trigger event, determine a torque offset of the power steering system based on output from the torque sensor, in response to the torque offset of the steering shaft exceeding a threshold for each of a plurality of occurrences of the trigger event, determine a torque offset correction value, and control a steering torque assistance applied by the power steering system to the steering assembly based on the torque offset correction value.
Corresponding reference characters indicate corresponding parts throughout the several views. The exemplification set out herein illustrates embodiments of the invention, and such exemplifications are not to be construed as limiting the scope of the invention in any manner.